Electrolytic marking device



July 9, 1957 A. R. LINDSAY ELECTROLYTIC MARKING DEVICE 2 shets-sheet 1 Filed Sept. 20, 19.54

y V R mW, m L. /YNT R A m Hh A '19199, 1951 A. R. LINDSAY 9 2,798,849

ELECTROLYTIC MARKING DEVICE Filed Sept' 2Q 1954 2 sheets-s119692 1N VEN TOR.

A ORA/EXE.

ELECTRGLYTIC MARKING DEVICE Allen R. Lindsay, Cleveland Heights, @bio Application September Z0, 1954, Serial No. 457,250

9 Claims. (Cl. 204-224) This invention relates as indicated to marking devices and, more particularly, to an improved construction for small, hand-manipulated stencil devices which use, and carry a charge of, a liquid in the marking operations performed thereby.

As thus broadly deiined, and as will appear more fully in the detailed description to follow, this class of marking instruments includes devices designed for the electrical etching of metal parts, wherein the liquid used is a suitable electrolyte, and also devices for marking objects with conventional inks, the basic structural improvements of the invention being adaptable to both types of marking procedures.

it is among the principal objects of the present invention to provide a hand-operated marker, including a liquid reservoir, of lightweight and durable construction, thereby to permit the same to be employed substantially continuously for prolonged periods without user fatigue and to enable the device to withstand rather rough handling.

Another object is to provide such a construction which embodies only a small number of parts and, accordingly, may be simply and inexpensively produced.

it is also an object to provide, in a marking device or the character indicated, an improved feed of the liquid from the reservoir to the active marking element of the device, such feed enhancing the convenience of use and uniformity of the marking produced by the device.

Another object of my invention is to provide a novel head for removably mounting a stencil assembly with the two so -structurally related as to afford ready engagement and disengagement thereof, whereby a number of stencil assemblies deiining different characters may quickly and conveniently be substituted in a single marking device equipped with such a head.

Another object is to provide improved means for sealing the Work-engaging portion of a marking device of this nature from the air when not in actual use, so that evaporation, in the case of an electrolyte and certain inks, and oxidation, where other ink types are employed, is eciently prevented.

Another object of this invention is to provide a novel storage mount for a hand marking tool which supports the same in readily accessible condition; also to provide such a mount assembly which includes means forsealing the active portion of the marker from the air.

A further object is to provide a new hand-manipulated device for marking with temporary stencils, such as those prepared on a typewriter for short run marking.

An additional object is to provide a simplified marker construction especially suited for stenciling with ink, characterized by having a large and easily iilled reservoir for the ink and improved means for feeding the same to the stencil member.

Other objects and advantages of the invention will become apparent as the following description proceeds.

To the accomplishment of the foregoing and related States Patent ice ends, the invention, then, comprises the features hereinafter fully described and particularly pointed out in the claims, the following description and the annexed drawings setting forth in detail certain illustrative embodiments of the invention, these being indicative, however, or but a few of the various ways in which4 the principle or" the invention may be employed.

in said annexed drawings:

Fig. 1 is a perspective view of a complete marking assembly in accordance with the invention, including an electro-etching type of marker, a protective cap therefor, and a mount for supporting the marker when not in use;

Fig. 2 is a longitudinal sectional view of the marker shown in Fig. l;

Fig. 3 is a transverse sectional view taken on the plane indicated by the line 3--3 in Fig. 2;

Pig. 4 is a vertical section illustrating the engagement of the marker with the cap and of the latter with the mount;

Fig. 5 is an exploded perspective view of the marker cartridge provided with stencil-retaining means adapting the same for use with temporary stencils;

Figs. 6 and 7 are side and end views, respectively, of a slightly modified head for use with relatively small stencils; and t Fig. 8 is a fragmentary view of a simplified form of the construction adapted particularly for ink stenciling.

Referring now to the drawings in detail, and especially to Figs. l to 4, the electroetching marker there illustrated is of cartridge type construction comprising a tubular holder l of a size such to be easily manipulated by hand. The holder, preferably made of a rigid plastic material, is open only at one end 2 of the same, and removably but snugly iitted therein is a cartridge including: a barrel 3, which forms a reservoir for electrolyte, and a head indicated generally at 4, both latter parts being made of a exible plastic material.

The head has a reduced end portion or neck S received in an end of the barrel 3 in liquid-tight engagement with the wall of the latter, a shoulder portion 6 of slightly larger diameter, and an enlarged outer portion 7, all integrally molded. In the particular form of head shown in the drawings, the outer portion 7 is circular but it may also be rectangular or of other desired shape. With the cartridge thus disposed in the holder, the lower end of the latter abuts the upper end of shoulder portion d of the head, so that this portion and the portion 7 project below the holder.

As indicated, the head is made of a flexible plastic, polyethylene being preferred for both the head and barrel, and a circular groove 8 is formed in its exposed end` face 9 so that the same is adapted to mount a cup-shaped stencil assembly designated generally by reference numeral ld. This stencil unit, which is self-supporting comprises an inner metallic screen 11, an intermediate layer of fabric l2 cemented to the screen, and an outer plastic stencil i3, the latter defining the desired characters. An absorbent pad i4 is arranged interiorly to overlie the body portion of the member, leaving the screen exposed at the inner sides.

Thus, the unitary stencil assembly has a contact or Work-engaging portion and a rearwardly extending continuous wall portion. Groove 3 of thehead is dimensioned such to receive the wall portion, with the same resiliently gripped therein and the contact portion disposed against the end face 9 of the head. The resiliency of the plastic makes possible this type of mounting, and, if desired, firmness of the engagement could be enhanced byforming the wall portion of the stencil member with a normal slight `outward taper. No other means need be employed to mount the stencil on the head, audit i will be seen that the two may very easily be engaged and disengaged.

The head is also provided with an axial bore l which is reduced to a capillary passage 16 at its outer end opening on the face 9 against which the stencil assembly is arranged. Accordingly, a suitable electrolyte stored in the reservoir will be fed by capillary action to such face and there absorbed by pad 14 and the fabric backing of the stencil member. The size of passage lo is of importance and should properly 'oe related to the viscosity of the liquid to provide` the optimum rate of liquid flow therethrough.

In the operation of this electroetching marker, a poten tial is applied between the metal work and the metallic screen 1l, so that the work will be electrolytically etched when the marking portion of the device is placed thereon, the electrolyte being active in the openings, indicated at 17, defined by the plastic, and hence dielectric, stencil. To facilitate connection of the screen to a source of electrical energy, head 4 has a metal ring t8 engaged about its shoulder portion 6 and a spring arm contact 19 held in contact with the ring and extending through the body of the head into the groove S where it is engaged by the exposed inner wall of the screen. This much of the electrical Contact arrangement is carried by the head and is detachable therewith from the holder.

The circuit of the marking device is completed by an elongated Contact member arranged against the inner wall of 'the holder to extend from the lower to the upper end portion of the same between such wall and the outer wall of barrel 3. If desired, the member may normally be bowed outwardly to assist in holding the barrel in place by spring action. At its lower end, member E@ is bent outwardly to pass through a notch 2l, formed in the holder wall for such purpose, and then downwardly and inwardly so that its terminal portion 22 acts as a Vspring contact engaging metal ring 18 of the cartridge head. Member 20 is secured to the holder by having its upper end portion slipped over a threaded metal stud 23, which extends through the holder wall, a nut Zd holding the member on the stud and the latter fastened to the holder. A wire 25 is connected to the outer end of the stud within an insulating sleeve 26 and to one terminal of a plug 27, the other terminal of which is adapted to bc connected by a wire 2S to the work, for example, by a contact clip. Connection of the plug to the energy source, therefore, establishes the working circuit.

ln order to prevent evaporation of the electrolyte water when the marker is not in use, there is provided a protective cap 29 made of fiexible plastic material, preferably polyethylene, having a wall 3i) which lits snugly about the wall of the enlarged portion 7 of the head and forms an air-tight seal therewith. This cap is formed with a reduced portion 3l, an end wall 32, and a rectangular projection 33 extending diametrically of the end wall. The reduction at portion 31 provides an inner shoulder 34 at the bottom of the head-engaging wall 30 against which the extreme peripheral portion of face 9 of the head is abutted and accordingly spaced from the end wall of the cap. The spacing is such that stencil assembly 10 is held out of contact with the cap being received in the larger recess formed by portions 3l thereof, to preclude any damage to the same bythe engagement of cap and marker.

The cap 29 is supported by a mount 35 in a condition such that it, in turn, may support the marker in upright condition, the amount being adapted to be secured to a supporting surface by suitable fastening means. Mount 35 is preferably made of a rigid plastic, such as polystyrene, shaped to provide an elongated recess 36 in the upper portion thereof which receives the projection 33 of the protective cap. Small, sharp ridges 37 are provided at the opposite longitudinal sides of the recess to function inthe manner of knife edges and, by biting into -the sides of the cap projection, to hold the same tightly engaged in the recess. The upper wall surfaces 38 immediately before such ridges are inclined downwardly so that the cap, while removable only with difliculty, can easily be snapped into the mount.

When assembled in this manner, cap 29 and mount 35 form a storage for the marker operative to support the Same in a readily accessible condition and at the same time seal the working face of the marker to prevent evaporation of the electrolyte water. It will be appreciated that the mount may be elongated thus to support a number of markers and associated caps in the same manner, the size and shape of the head-enclosing cap portions corresponding to the particular heads employed but all having a similar rectangular projection for engagement with the mount. Also, that caps of the nature described may be used, if desired, independently of the mounting strip, for example, a marker could have, in effect, two caps, one engaged in the mount for storage as indicated and another loose cap for sealing the marker head during relatively short interruptions in use.

In Fig. 5, the cartridge comprising barrel 3 and head 4', as previously described, is provided with a flexible plastic sleeve 39 adapted to lit snugly about the enlarged portion 7 of the head in much the same manner as the resilient wall 30 of the protective cap. In fact, the sleeve may be made from the cap by cutting the same to remove the end wall 32, with the cap shoulder, however, being left to form an inwardly directed ange 4d at one end of the resultant sleeve. This sleeve adapts the cartridge for marking with typewriter prepared stencils, one of which is indicated at 41. In such an application of the marker, the plastic stencil previously described is, of course, omitted from the cup-shaped assembly 16 and replaced by stencil 41 arranged against the fabric layer t2. rlhis stencil is of a size such that its edges are folded back about the head, so that the sleeve firmly holds the same in place with flange 40 overlying the peripheral portion of the operative stencil face.

When the size of the stencil, and accordingly the head, is relatively large, a number of grooves as shown at 42 in Fig. 5 may be cut or formed in the end face 9 of the cartridge head to assist in distributing the liquid supplied through the axial opening 16. The slightly modified head shown in Figs. 6 and 7 is preferred for Small stencils and differs from the form previously described by an outward stepping down of the diameter, providing an enlarged contact portion 43 having a metal ring 44 engaged thereabout, an intermediate portion 45 of slightly reduced diameter, and a projecting terminal portion 46 of still smaller size. The stencil-retaining groove 47 is here formed between the portions 45 and 46, and contact finger 48 adapted to engage the metallic screen of the stencil assembly is bent inwardly and then downwardly to be disposed against the inner wall of the groove and the outer surface of the projecting portion 46. This head .is also provided with a capillary opening 49 and is operative in the manner set forth earlier.

The construction disclosed in the above is adapted for marking with ink, as well as electrical etching, the electrical contact members being omitted from the holder and head when ink is employed. In both cases, the barrel 3 forming the liquid reservoir may very easily be lled and, due to its flexibility, can be squeezed to prime the device by forcing an initial quantity of liquid through the capillary opening. When intended solely for use with ink, so that no contact assembly is actually needed, greater storage capacity can be had by the modication shown in Fig. 8, wherein the neck portion 5' of the head is made of larger diameter to lit tightly within the holder 1', the engagement forming a liquid seal. The opening for the contact stud is here omitted, whereby the holder is completely closed and adapted to contain the ink.

It will accordingly be seen that the invention provides an extremely versatile marker construction, which nonethe less consists of only a small number of parts. The

use of a iiexible plastic material, such as polyethylene, for` the head, `barrel and cap affords the simplified yet efficient mounting of the stencil assemblies, the easy separation of the head from the barrel for convenient filling of the latter, and the effective sealing action of the cap. Likewise, a seal may be had between the head and the plastic holder by a simple sliding fit, as illustrated in Fig. 8, and the barrel held firmly in the holder in the Fig. 2 form of the construction without separate fastening means.

While polyethylene is the preferred material for those parts of the assembly described as being flexible, other flexible plastics having similar properties and affording the noted characteristics, of which nylon and polyvinyl chloride are specific examples, may be substituted. Both the cartridge holder andthe mounting strip are preferably made of polystyrene, but could also be formed of a phenolic resin or hard rubber, among other suitable materials, if desired.

The capillary feed provided by my new cartridge head eliminates any need for valve or ejection mechanism, however simple, requiring to be manipulated by the operator and insures uniform results. This and the other advantages noted, of course, obtain whether an electrolyte or ink is used, and it will be understood that any suitable stencil element, whether of plastic-engraved, photosensitive, die-impressed or other type, may be employed as desired.

Other modes of applying the principle of the invention may be employed, change being made as regards the details described, provided the features stated in any of the following claims, or the equivalent of such, be employed.

I therefore particularly point out and distinctly claim as my invention:

l. In a marking device, a self-supporting stencil assembly including a metallic screen shaped to provide a work-engaging portion and a continuous rearwardly extending wall portion, a head made of flexible plastic material removably mounting said stencil assembly, said head comprising a support surface overlain by such workengaging portion of said stencil assembly and a groove within which the wall portion of the assembly is resiliently gripped, the head further having a reduced end portion at the rear of the same and being provided with a capillary opening extending completely therethrough, a iiexible plastic barrel open only at one end and tightly engaged at such end about the reduced end portion of said head, said barrel being adapted to contain a quantity of liquid used in the marking operation with the same supplied therefrom to said stencil assembly by the capillary action of such opening in the head, and a portable tubular holder made of substantially inflexible plastic material within which said barrel is snugly iitted, the head attached to said barrel projecting from an end of said holder for use therewith in the marking operation.

2. An electroetching device comprising a self-supporting stencil assembly of general cup-shape including a metallic screen, a portion of which extends to the rear with the liange of the assembly, absorbent material, and a dielectric stencil; a exible plastic mount for said assembly provided with a groove in a face thereof within which the flange portion of said assembly is resiliently gripped and a capillary passage opening on such face; electrical contact means for energizing said screen including a metal arm which passes through the body of said plastic mount and into such groove for engagement with the rearwardly extending portion of the screen received in the groove; a barrel made of fiexible plastic material attached to said mount and adapted to hold a quantity of electrolyte in communication with the end of such capillary passage opposite that opening on the face of the mount against which the stencil assembly is disposed, whereby electrolyte will continuously be supplied in operation to the stencil assembly by the capillary action of the passage; anda substantially inexible plastic holder Within which said barrel is snugly fitted such that said mount projects beyond an end of the holder for use therewith, said holder carrying conductor means for connecting said contact arm engaged with the screen to a source of electrical energy. f

3. A `marking device comprising, in combination, a portable reservoir for liquidy used in a marking operation, a exible plastic head attached to said reservoir `adapted to mount a cup-shaped stencil assembly with the wall portion of the latter resiliently gripped in a groove formed in the outer face of said head, a protective plastic cap having a flange adapted releasably to engage about said head and seal the outer face of the same from the air, said cap being formed with an inner shoulder which engages such face of the head outwardly with respect to such groove and spaces the area of the face defined by the groove a predetermined distance from the closed end of the cap, the spacing being such to maintain the body portion of the stencil assembly overlying such face of the head out of contact with the cap end, said cap further having a generally rectangular projection `at the closed end of the same, and a mounting strip provided with an opening adapted to receive such projection of the cap `having knife edges at the sides thereof operative by engagement with the projection to prevent ready removal of the cap from the strip, whereby the reservoir and head attached thereto may be supported by the thus engaged cap and strip and withdrawn as a unit therefrom for use in marking operations.

4. In an electrolytic marking device, a holder in the form of a plug-like body made of a resiliently deformable material, said 4body having an end face in which there is provided an endless generally axially directed groove, a self-supporting generally cup-shaped backing device adapted to support a stencil on its bottom outer face, said backing device including a metallic screen electrode and absorbent material for holding a charge of an electrolyte, the backing device being removably secured to said holder by having its wall portion resiliently gripped in the groove in such end face of the body, with the bottom of the backing device substantially uniformly against and thus supported by such end face, a dielectric stencil held against the bottom outer face of said backing device, and a passageway through the body terminating proximate to a portion of said metallic screen for reception of electrical conductor means in contact with the screen.

5. In an electrolytic marking device, a holder in the form of a plug-like body made of a resiliently deforma* ble material, said body having an end face in which there is provided an endless generally axially directed groove, a self-supporting generally cup-shaped backing device adapted to support a stencil on its bottom outer face, said backing device including a metallic screen electrode and absorbent material for holding a charge of an electrolyte, the backing device being removably secured to said holder by having its wall portion resiliently gripped in the groove in such end face of the body, with the bottom of the backing device substantially uniformly against and thus supported by such end face, a dielectric stencil held against the bottom outer face of said backing device, an elongated handle vto which said holder is detachably secured for manipulation, and electrical conductor means carried by said handle, said con ductor means extending through the holder into contact with the metallic screen. t

6. In an electrolytic marking device, a holder in the form of a plug-like body made of a resiliently deformable material, said body having an end face in which there is provided` an endless generally axially directed groove, that portion of said end face bounded by the groove projecting outwardly of the remainder of the face, a self-supporting general-ly cup-shaped backing device adapted to support a stencil on its bottom outer face, said backing including a metallic screen electrode and absorbent material for holding a charge of an electrolyte, the backing device being removably secured to said holder by having its wall portion resiliently gripped in the groove in such end face of the body, with the bot- Vsaid metallic screen for reception of electrical conductor means to contact the same.

7. In an electrolytic marking device, a holder in the form of a plug-like body made of a resiliently deformable material, said body having an end face in which there is provided an endless generally axially directed groove and a liquid orifice which extends through the body to that portion of the end face bounded by such groove, a self-supporting generally cup-shaped backing device adapted to support a stencil on its bottom outer face, said backing device including a metallic screen electrode and absorbent material for holding a charge of an electrolyte, the backing device being removably secured to said holder by having its wall portion resiliently gripped in the groove in such end face of the body, with the bottom of the backing device substantially uniformly against and thus supported by such end face, a dielec- Ytric stencil held against the bottom outer face of said backing device, a passageway through the body terminating proximate to a portion of the metallic screen for accommodation of electrical conductor means in contact with the same, and a portable reservoir for electrolyte connected to said holder in communication with the liquid oriiice thereof for supply of the electrolyte through the orifice to the absorbent material of said backing device.

8. In an electrolytic marking device, a holder in the form of la plug-like body made of a resiliently deformable material, said body having an end face in which there 'is provided an endless generally axially directed groove,

a self-supporting generally cup-shaped backing device adapted to support a stencil on its bottom outer face, said backing device including a metallic screen electrode and absorbent material for holding the charge of electrolyte, the backing device being removably secured to said holder by having its wall portion resiliently gripped in the groove in such end face of the body, with the bottom of theV backing device substantially uniformly against and thus supported by such end face, `a sheet having a stencill portion disposed against the outer bottom face of said backing device and having a marginal portion folded back about the end of ythe holder, a sleeve fitted on such end of the holder over the folded back portion of the sheet to grip the same cooperably with the outer surface of the holder, and an opening in the body having an end adjacent the metallic screen for reception of electrical conductor means in contact with the screen.

9. In an electrolytic marking device, aholder in the form of a plug-like body made of a resiliently deformable material, said body having an end face in which there is provided an endless generally axially directed groove, a self-supporting generally cup-shaped backing device adapted to support a stencil on its bottom outer face, said backing device including Ia metallic screen electrode and absorbent material for holding a charge of an electrolyte, the backing device being removably secured to said holder by havingits wall portion resiliently gripped in the groove in such end face of the body, the bottom of the backing device substantially uniformly `against and thus being supported by such end face, electrical conductor means extending through the body into contact with said metallic screen, a capillary opening through the holder with one end thereof occurring at the portion of the end face bounded by such groove, and a barrel Vattached to the holder forming a chamber for a quantity of electrolyte which is supplied to the stencil assembly by the capillary action of such opening in the holder.

References Cited in the le of this patent UNITED STATES PATENTS 828,814 Cunningham Aug. 14, 1906 938,098 Wilkoshesky Oct, 26, 1909 1,782,877 Madden Nov. 25, 1930 2,104,676 Senf Ian. 4, 1938 2,110,007 Teit Mar. 1, 1938 2,288,015 Mumma June 30, 1942 2,316,040 Wirfel Apr. 6, 1943 2,498,129 Lindsay Feb. 21, 1950 2,584,908 Oblinger Feb. 5, 1952 2,600,413 Mason et al June 17, 1952 

1. IN A MARKING DEVICE, A SELF-SUPPORTING STENCIL ASSEMBLY INCLUDING A METALLIC SCREEN SHAPED TO PROVIDE A WORK-ENGAGING PORTION AND A CONTINUOUS REARWARDLY EXTENDING WALL PORTION, A HEAD MADE OF FLEXIBLE PLASTIC MATERIAL REMOVABLY MOUNTING SAID STENCIL ASSEMBLY, SAID HEAD COMPRISING A SUPPORT SURFACE OVERLAIN BY SUCH WORKENGAGING PORTION OF SAID STENCIL ASSEMBLY AND A GROOVE WITHIN WHICH THE WALL PORTION OF THE ASSEMBLY IS RESILIENTLY GRIPPED, THE HEAD FURTHER HAVING A REDUCED END PORTION AT THE REAR OF THE SAME AND BEING PROVIDED WITH A CAPILLARY OPENING EXTENDING COMPLETELY THERETHROUGH, A FLEXIBLE PLASTIC BARREL OPEN ONLY AT ONE END AND TIGHTLY ENGAGED AT SUCH END ABOUT THE REDUCED END PORTION OF SAID HEAD SAID BARREL BEING ADAPTED TO CONTAIN A QUANTITY OF LIQUID USED IN THE MARKING OPERATION WITH THE SAME SUPPLIEDION THEREFROM TO SAID STENCIL ASSEMBLY BY THE CAPILLARY ACTION OF SUCH OPENING IN THE HEAD, AND A PORTABLE TUBULAR HOLDER MADE OF SUBSTANTIALLY INFLEXIBLE PLASTIC MATERIAL WITHIN WHICH SAID BARREL IS SNUGLY FITTED, THE HEAD ATTACHED TO SAID BARREL PROJECTING FROM AN END OF SAID HOLDER FOR USE THEREWITH IN THE MARKETING-OPERATION. 